Rxjava学习笔记

1、使用Observable.range(int start, int count)创建一个发射特定整数序列的Observable，第一个参数为起始值，第二个为发送的个数，如果为0则不发送，负数则抛异常。

import rx.Observable;
import rx.Subscriber;

public class MyDemo {

    public static void main(String[] args) {
        //创建发射源（被观察者）
        Observable<Integer> observable = Observable.range(1, 5);
        //创建接收源（观察者）
        Subscriber<Object> subscriber = new Subscriber<Object>() {
            @Override
            public void onStart() {
                System.out.println("Subscriber onStart: ");
            }

            @Override
            public void onCompleted() {
                System.out.println("Subscriber onCompleted: ");
            }

            @Override
            public void onError(Throwable e) {
                System.out.println("Subscriber onError: " + e.toString());
            }

            @Override
            public void onNext(Object t) {
                System.out.println("Subscriber onNext: " + t);
            }
        };
        //订阅
        observable.subscribe(subscriber);
    }
}

2、Subscriber的简化

RxJava提供了Action0等一系列的类似的类，当我们不需要（或者不关心）Subscriber的全部方法（如只关心onNext方法），就可以使用Action类来替代Subscriber。

2.1、当我们并不关心OnComplete和OnError，可以使用 subscribe(onNextAction)，我们只需要在onNext的时候做一些处理，这时候就可以使用Action1类：

import rx.Observable;
import rx.functions.Action1;

public class MyDemo {

    public static void main(String[] args) {
        Person person = new Person(21, "js");
        //创建发射源（被观察者）
        Observable<Person> observable = Observable.just(person);
        //订阅，创建接收源（观察者）
        observable.subscribe(new Action1<Person>() {

            @Override
            public void call(Person t) {
                System.out.println("Action1 call:" + t.toString());
            }
        });
    }
    private static class Person{
        private int age;
        private String name;
        
        public Person(int age, String name) {
            this.age = age;
            this.name = name;
        }

        public int getAge() {
            return age;
        }
        public void setAge(int age) {
            this.age = age;
        }
        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
        
        @Override
        public String toString() {
            return "Person[age=" + age + ",name=" + name + "]" ;
        }
    }
}

2.2、subscribe方法还有两个重载方法，分别是：

• 两个参数： subscribe(onNextAction , onErrorAction)
• 三个参数： subscribe(onNextAction , onErrorAction ,onCompletedAction)

import rx.Observable;
import rx.functions.Action0;
import rx.functions.Action1;

public class MyDemo {

    public static void main(String[] args) {
        Person person = new Person(21, "js");
        //创建发射源（被观察者）
        Observable<Person> observable = Observable.just(person);
        //订阅，创建接收源（观察者）
        Action1<Person> onNextAction = new Action1<Person>() {
            @Override
            public void call(Person t) {
                System.out.println("Action1 call:" + t.toString());
            }
        };
        Action1<Throwable> onErrorAction = new Action1<Throwable>() {
            @Override
            public void call(Throwable t) {
                System.out.println("Action1 call:" + t.toString());
            }
        };
        Action0 onCompletedAction = new Action0() {
            @Override
            public void call() {
                System.out.println("Action0 call");
            }
        };
        observable.subscribe(onNextAction, onErrorAction);
        observable.subscribe(onNextAction, onErrorAction, onCompletedAction);
    }
    private static class Person{
        private int age;
        private String name;
        
        public Person(int age, String name) {
            this.age = age;
            this.name = name;
        }

        public int getAge() {
            return age;
        }
        public void setAge(int age) {
            this.age = age;
        }
        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
        
        @Override
        public String toString() {
            return "Person[age=" + age + ",name=" + name + "]" ;
        }
    }
}